cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A307282 Sprague-Grundy values for Maharaja Nim on the counterclockwise square spiral.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 4, 6, 5, 7, 9, 8, 10, 1, 9, 2, 10, 3, 9, 11, 10, 2, 0, 3, 11, 10, 4, 1, 0, 6, 12, 7, 5, 3, 0, 8, 7, 1, 4, 5, 0, 2, 1, 12, 13, 6, 7, 1, 14, 8, 12, 3, 2, 9, 8, 10, 3, 2, 13, 4, 6, 7, 11, 13, 6, 12, 15, 14, 16, 8, 10, 7, 14, 4, 5, 3, 15
Offset: 0

Views

Author

N. J. A. Sloane, Apr 05 2019

Keywords

Comments

A Maharaja is a piece which can move both like a queen and a knight.
A274641 is the analogous sequence if the piece is a chess queen.

Examples

			The counterclockwise square spiral begins:
.
  16--15--14--13--12
   |               |
  17   4---3---2  11   .
   |   |       |   |
  18   5   0---1  10   .
   |   |           |
  19   6---7---8---9   .
   |
  20--21--22--23--24--25
.
		

Crossrefs

For the P-positions see A307283.

Programs

  • PARI
    See Links section.

Extensions

More terms from Rémy Sigrist, Apr 06 2019

A307284 Coordinates X_upper(n) of P-positions in Maharaja Nim on square spiral (see Comments for precise definition).

Original entry on oeis.org

0, 2, 4, 7, 8, 11, 12, 14, 16, 18, 21, 24, 26, 28, 29, 31, 32, 34, 36, 38, 40, 42, 43, 45, 46, 48, 49, 51, 54, 55, 57, 60, 61, 63, 64, 66, 68, 71, 72, 74, 75, 77, 80, 81, 83, 86, 87, 89, 92, 93, 95, 97, 98, 100, 103, 104, 106, 108, 109
Offset: 0

Views

Author

N. J. A. Sloane, Apr 08 2019

Keywords

Comments

We study Maharaja Nim on the square spiral, as in A307282, A307283, and in particular the P-positions in the 4th quadrant. As in A140100 and A140101 (which are the analogs if we use a Queen instead of a Maharaja) we take the X-axis to point South and the Y-axis to point East.
The P-positions now lie on two roughly straight lines, with coordinates (X_upper(n), Y_upper(n)) with X_upper(n) <= Y_upper(n), and (X_lower(n), Y_lower(n)) with X_lower(n) <= Y_lower(n). These four sequences are A307284-A307287.
The two lines are the hard-to-see black pixels in the fourth quadrant in the Sigrist illustration.

Crossrefs

A307287 Coordinates Y_lower(n) of P-positions in Maharaja Nim on square spiral (see Comments for precise definition).

Original entry on oeis.org

0, 1, 9, 13, 19, 22, 37, 52, 58, 69, 78, 84, 90, 101, 112, 118, 132, 138, 149, 160, 171, 180, 191, 200, 211, 222, 228, 237, 248, 259, 268, 279, 288, 299, 308, 319, 325, 336, 345, 356, 362, 373, 382, 393, 402, 413, 424, 430, 441, 450, 461, 470, 481, 487, 498
Offset: 0

Views

Author

N. J. A. Sloane, Apr 08 2019

Keywords

Comments

We study Maharaja Nim on the square spiral, as in A307282, A307283, and in particular the P-positions in the 4th quadrant. As in A140100 and A140101 (which are the analogs if we use a Queen instead of a Maharaja) we take the X-axis to point South and the Y-axis to point East.
The P-positions now lie on two roughly straight lines, with coordinates (X_upper(n), Y_upper(n)) with X_upper(n) <= Y_upper(n), and (X_lower(n), Y_lower(n)) with X_lower(n) <= Y_lower(n). These four sequences are A307284-A307287.
The two lines are the hard-to-see black pixels in the fourth quadrant in the Sigrist illustration.

Crossrefs

Extensions

More terms from Rémy Sigrist, Apr 09 2019

A307286 Coordinates X_lower(n) of P-positions in Maharaja Nim on square spiral (see Comments for precise definition).

Original entry on oeis.org

0, 5, 17, 25, 35, 41, 67, 96, 107, 127, 144, 155, 166, 186, 206, 217, 243, 254, 274, 294, 314, 331, 351, 368, 388, 408, 419, 436, 456, 476, 493, 513, 530, 550, 567, 587, 598, 618, 635, 655, 666, 686, 703, 723, 740, 760, 780, 791, 811, 828, 848, 865, 885, 896
Offset: 0

Views

Author

N. J. A. Sloane, Apr 08 2019

Keywords

Comments

We study Maharaja Nim on the square spiral, as in A307282, A307283, and in particular the P-positions in the 4th quadrant. As in A140100 and A140101 (which are the analogs if we use a Queen instead of a Maharaja) we take the X-axis to point South and the Y-axis to point East.
The P-positions now lie on two roughly straight lines, with coordinates (X_upper(n), Y_upper(n)) with X_upper(n) <= Y_upper(n), and (X_lower(n), Y_lower(n)) with X_lower(n) <= Y_lower(n). These four sequences are A307284-A307287.
The two lines are the hard-to-see black pixels in the fourth quadrant in the Sigrist illustration.

Crossrefs

Extensions

More terms from Rémy Sigrist, Apr 09 2019

A307285 Coordinates Y_upper(n) of P-positions in Maharaja Nim on square spiral (see Comments for precise definition).

Original entry on oeis.org

0, 3, 6, 10, 15, 20, 23, 27, 30, 33, 39, 44, 47, 50, 53, 56, 59, 62, 65, 70, 73, 76, 79, 82, 85, 88, 91, 94, 99, 102, 105, 110, 113, 116, 119, 122, 125, 130, 133, 136, 139, 142, 147, 150, 153, 158, 161, 164, 169, 172, 175, 178, 181, 184, 189, 192, 195, 198, 201
Offset: 0

Views

Author

N. J. A. Sloane, Apr 08 2019

Keywords

Comments

We study Maharaja Nim on the square spiral, as in A307282, A307283, and in particular the P-positions in the 4th quadrant. As in A140100 and A140101 (which are the analogs if we use a Queen instead of a Maharaja) we take the X-axis to point South and the Y-axis to point East.
The P-positions now lie on two roughly straight lines, with coordinates (X_upper(n), Y_upper(n)) with X_upper(n) <= Y_upper(n), and (X_lower(n), Y_lower(n)) with X_lower(n) <= Y_lower(n). These four sequences are A307284-A307287.
The two lines are the hard-to-see black pixels in the fourth quadrant in the Sigrist illustration.

Crossrefs

Showing 1-5 of 5 results.